Just last week, Apple made waves by investing $1 billion into Chinese ride-hailing giant Didi Chuxing, its first disclosed private investment in recent years. The deal was just the third $1B+ equity financing round of 2016 to-date.

The top ride-hailing companies have raised some of largest mega-deals that private markets have ever seen, in order to finance their fierce competition across the globe. We used the CB Insights Business Social Graph, which maps the relationships between investors and companies, to map out the investor networks of the 5 most well-capitalized ride-hailing companies, including Didi Chuxing as well as Uber, Lyft, Olacabs, and Grab.

We used this social graph and the CB Insights database to pull further insights on the data:

Uber remains the most well-capitalized: Despite Didi Chuxing’s recent windfall, Uber still sits atop the group of most well-financed ride-hailing companies, with $8.01B raised to date. Inclusive of the Apple investment, Didi Chuxing ranks second with $6.28B ($725M to Kuaidi Dache, $818M to Didi Dache, and $4.74B to the merged entity). Lyft comes in third, having raised $1.6B to date.

Didi itself is actively investing in Uber competitors: Interestingly, Didi Chuxing itself has invested directly in every top-5 ride-hailing startup besides Uber, including Lyft, Olacabs, and Grab. These companies have formed a loose coalition in the hopes of competing against Uber and its large war chest.

A variety of corporates are searching for opportunities: Speculation is that Apple may be seeking leverage its investment in Didi to advance self-driving vehicle development (among several other potential motivations). However, General Motors has already made such intentions clear, with a $500M corporate minority round to Lyft and a joint announcement with the Uber competitor to deploy self-driving taxis by 2017. Additionally, Chinese internet giants such as Tencent and Alibaba have invested in both Didi and Lyft. Other corporates such as Ping An Insurance and Microsoft have also invested in at least one of these companies.

Non-traditional investors active in this arena: Other investors that usually focus on other asset classes have made notable investments these private ride-hailing companies. Hedge funds (Tiger Global, Coatue), mutual funds, and sovereign wealth funds have all participated in a number of financing rounds.

Four investors have stakes in three different companies: Tiger Global Management and SoftBank have invested in each of the Asian ride-hailing giants (Didi Chuxing, Olacabs, and Grab). Hedge fund Coatue Management has a stake in Lyft, Didi, and Grab. Hillhouse Capital is an interesting case, having invested in Uber as well as Didi and Grab. These investors are highlighted as the smaller logos in our business social graph.